import React from "react";

interface Animal {
  name: string;
}
interface Cat {
  name: string;
  run(): void;
}

function testAnimal(animal: Animal) {
  return (animal as Cat);
}
function testCat(cat: Cat) {
  return (cat as Animal);
}
const Demo1 = () => {
  return <div>我是demo1</div>;
};
